1. Field of the Invention
The present invention relates to an information processing apparatus, and more specifically to an apparatus and method for use in an information processing apparatus provided with an information storage device in which a plurality of storage media having different accessibility are hierarchically structured.
2. Description of the Related Art
A hierarchically-structured information storage device including a plurality of storage media having different accessibility is commonly used to efficiently store a large volume of data in an information storage device. A large volume of data can be stored without deterioration in accessibility by hierarchically combining, for example, high-access-speed and small-capacity cache memory, an intermediate hard disk, a low-access-speed and large-capacity magnetic disk, etc.
When the above described hierarchically-structured information storage device is combined with a file management system for controlling access to files containing actual data, there is a request to store, in a storage medium having high accessibility, various attribute information about files, etc. such as information for file access to improve the function of retrieving data in the file. On the other hand, there also is a contradictory request to store the attribute information, etc. in a portable storage medium, that is, in a lower order hierarchical level, to use a portable media such as an MO (magneto-optical disk) independently offline.
On the other hand, in a hierarchically-structured information storage device storing a large volume of data, it is necessary to multiplex data to cover any accidental cases. For example, it is possible to multiplex data by processing the entire hierarchically-structured information storage device logically as a single volume, that is, a logic volume, and providing a spare logical volume. In such a case, there arises a request to store attribute information in a portable storage medium to independently use the portable storage medium offline as described above.
The present invention has been developed to solve the above described problems, and aims at efficiently accessing data in a hierarchically-structured information storage device by storing or moving information required to access files and attribute information about the files in or to a storage medium at an appropriate hierarchical level depending on the situation. In addition, when a spare logical volume is provided in logical volume units, similar control can be performed to efficiently access data in the spare logical volume.
In an information processing device having an information storage device in which a plurality of storage media having different accessibility are hierarchically combined, the present invention includes: a first control unit for storing data for use in accessing a file in a portable storage medium storing only the body of the file, and then allowing the portable storage medium to be retrieved from the information storage device; a second control unit for allowing a portable storage medium storing only the body of a file without storing data for use in accessing the file to be retrieved from the information storage device; and a file retrieval request unit for allowing either the first control unit or the second control unit to control an external request to retrieve the portable storage medium.
In addition, in an information processing device in which a plurality of storage media having different accessibility form one logical volume, and contain a spare logical volume storing data in the logical volume for use in multiplexing the data in the logical volume, the present invention controls either the first control unit or the second control unit in response to a request to retrieve a portable storage medium in the spare logical volume.
According to the present invention, in an information processing device in which a plurality of storage media having different accessibility are hierarchically structured, an information storage device can be more efficiently utilized by moving and storing file attribute information required to retrieve a file, etc. and the body of the file to and in a storage media at an appropriate hierarchical level depending on the situation. Furthermore, when a spare logical volume is provided in logical volume units of the information storage device, data in the spare logical volume can also be efficiently accessed.